1. Field of the Invention
This invention relates to a system for continuously detecting the operational position of an automotive steering gear.
2. Disclosure Information
It is necessary with several types of automotive control systems to know the precise steering location of the road wheels, or in other words, the operational position of the steering gear. For example, systems which control adjustable shock absorbers according to the sensing of steering angles such as the systems illustrated in U.S. Pat. No. 4,621,833, rely upon the sensing of the steering position of the wheels. The U.S. Pat. No. '833 discloses a system for detecting rotational position of a steering driveshaft which is connected in turn to a steering gear. This system of the U.S. Pat. No. '833 is not, however, well suited for use with a remote mounted steering gear, unless such steering gear is driven by a mechanical driveshaft originating at the front steering gear Accordingly, it is an object of the present invention to provide a steering sensing system for detecting the operational position of an automotive steering gear which is suitable for use with a remotely mounted steering gear such as that employed with the rear wheels of four wheel steering systems U.S. Pat. No. 4,671,523 discloses an externally mounted sensor for detecting the position of the steered rear wheels of a vehicle having a four wheel steering system. Other systems employ additional sensors such as a linear variable differential transformer (LVDT) for the purPose of detecting the rear wheel steering position. Such sensors are subject to maladjustment and generally increase the space requirement for the electronic package mounted within the steering gear. It is a further object of the present invention to provide a steering gear position sensor which minimizes the additional space, weight and complexity requirements.
U.S. Pat. No. 4,785,901 discloses a rack end signal generating system in which only the extreme left and right steering positions of a steering rack are detected; such a system cannot provide information for controlling a steering gear throughout its full travel.
It is an advantage of the present invention that a sensor system according to this invention is compatible for use not only with remotely mounted rear wheel steering gears but also main steering gears employed at the front wheels of the vehicle.
It is an advantage of the system according to the present invention that the sensor system may be employed for continuously and reliably detecting the position of a steering gear as the steering gear moves the roadwheels from one extreme position to the other extreme of the possible steering positions.
Other objects, features and advantages of the present invention will become apparent to those skilled in the art upon reading this specification.